When the 8472 station arms its weapons Janeway orders the Delta Flyers weapons armed. However, she had already ordered them armed only moments before.

Great Moment :

The first sight of Star Fleet command.

Body Count :

One 8472 dies on Voyager, another "reverts" in the bar, but apparently that's not fatal.

Factoid :

Writer Nick Sagan's voice was sent into space in 1978 on NASA's Voyager spacecraft. His greeting, "Hello from the children of planet Earth"

We get another crew count in this episode. Having tested Tuvok and Chakotay to see if they are 8472, the EMH announces "Two down, one hundred and twenty five to go." Assuming he would not be part of the testing process, that's 128 in all.

Plotline

Voyager discovers a perfect replica of Starfleet academy floating around in the Delta Quadrant. But it's really a training ground for Species 8472 which will allow them to infiltrate Starfleet and launch an attack on Earth.